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74 IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 RIVAS

Green Anacondas (Eunectes murinus) are the most widely distributed species of anacondas. Although some pythons may attain greater
lengths, no other snake is as massive. These snakes are found in most tropical lowland habitats east of the Andes. Although any use of
the Green Anaconda is prohibited by Venezuelan law, illegal harvests are common. Between 1988 and 1990, international authorities
confiscated 2,138 anaconda skins in Holland that supposedly originated in Venezuela. 

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Many biologists consider economics and politics to be bad
words. Because we are not trained in their use and impli-

cations, we often prefer to avoid issues that involve those topics.
Consequently, when we discuss the economics of conservation,
we usually talk about economic incentives for conservation and
sustainable use of natural resources, but often fail to delve more
deeply. We identify the cost of a commodity from nature, what
its exploitation represents from an environmental perspective,
and what economic incentives might filter down to the popu-
lace, but we almost always lose sight of the larger macroeco-

nomic framework in which such discussion belongs. For this
reason, the solutions we offer often fail to address the real eco-
nomic needs of both natural and human communities, and our
proposed solutions frequently are vulnerable to fiscal and polit-
ical pressures that fail to consider that the environment is more
than a source of commodities. Herein, I will discuss the macro-
economic situation in Latin America and the impact that poli-
tics and economic policies have had on conservation, and specif-
ically how these affect anacondas and related conservation issues
in South America.

Conservation of Green Anacondas:
How Tylenol Conservation and 

Macroeconomics Threaten the Survival 
of the World’s Largest Snake

Jesus A. Rivas

Department of Mathematics and Natural Sciences, Somerset Community College, Somerset, Kentucky

IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 75CONSERVATION OF GREEN ANACONDAS

�

Capturing Green Anacondas can be difficult. Although snakes are large and can inflict painful bites, they move slowly compared to many smaller
snakes, and can be handled safely by experienced personnel.

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The Problem of Conservation
Visitors to rural areas of Latin America have enjoyed beautiful
landscapes and pristine natural ecosystems alongside the less-
pleasurable experiences of seeing how the local people live. Their
economic limitations and struggles make it immediately clear
that no amount of education or enforcement of regulations can
(and should?) prevent them from using natural resources for
their own survival (McSweeney 2005). People living in a money-
driven system with few means of obtaining money are easily per-
suaded to exploit nature in an unsustainable fashion. The sale of
wildlife is a common example (e.g., Fitzgerald et al. 1991,
Robinson and Redford 1991, Vickers 1991). Whether they use
nature unsustainably of their own accord, due to lack of educa-
tion and environmental awareness, or are encouraged (or forced)
by external commercial interests (e.g., Camhi 1995), abject
poverty is the primary problem and no conservation program
can succeed without addressing it.

Neoliberal Economic Policies
For the last half century, international economic agencies (IEAs),
such as the World Bank (WB), the International Monetary
Fund (IMF), and the United States Agency for International
Development (USAID), have been actively promoting develop-
ment by injecting money into the national economies of under-
developed nations. The idea is to stimulate those economies,
eventually providing countries with the means to pay back the
money received (e.g., World-Bank 2001, Kütting 2004, Clapp

and Dauvergne 2005). However, reality differs; nations that have
received the most economic “help” have experienced dramatic
increases in poverty (e.g., Buhdoo 1994, Rich 1994, Jochnick
2001, Navarro-Jimenez 2004). The problem seems to be that
help comes with strings attached. These “strings,” called struc-
tural adjustment programs (SAPs), may include decreasing or
eliminating internal subsidies for agriculture, dropping trade
barriers, allowing international companies to operate in the

76 IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 RIVAS

During the breeding season, as many as 13 male Green Anacondas have been observed competing to mate with a single female, with the mating
aggregation lasting as long as four weeks. Here, eight males court a female in Venezuela. Females may mate with more than one male during the
breeding season. 

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Capable of taking large prey, Green Anacondas, nevertheless, are often
injured during the struggle. This snake is ingesting a Capybara
(Hydrochaeris hydrochaeris), which inflicted the bite responsible for the
large wound. 

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IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 77CONSERVATION OF GREEN ANACONDAS

country, granting exceptions to environmental regulations, elim-
inating social benefits, and relaxing labor laws.

Also, money must often be used to hire specific transna-
tional companies. Such entities are known as export credit agen-
cies (ECAs) and often are associated with the government of a
developed country. Consequently, much of any loan never
reaches the country it is supposed to benefit, moving instead
from one bank account to another in a developed nation (e.g.,
Goldzimer 2003, Perkins 2004, Clapp and Dauvergne 2005).
ECAs hire employees at minimum wage, but since SAPs impose
lower wages and drop social assistance and workers’ benefits, the
minimum wage does not really address poverty. People have
jobs, but the costs of essential commodities (produce, water,
housing) have gone up because the workers are now part of a
global market. Consequently, the local standard of living drops
(e.g., Horta 1991, Cheru 1992, Yunus 1994).

Such a neoliberal agenda can lead to environmental degra-
dation. People use resources in an unsustainable manner and
companies dump pollutants (in part due to the lowering of envi-
ronmental standards originally intended to spur economic
growth). Both result in habitat deterioration (e.g., Horta 1991,
Cheru 1992, Rich 1994, Pearce et al. 1995, Horta et al. 2002).
Especially when companies are temporary, like those involving

mining or logging, departure leaves behind pollution, destroyed
habitat, unemployment, and even more poverty than existed
previously (e.g., Goldzimer, 2003). One example is Argentina,
which embraced a neoliberal agenda wholeheartedly during the
late 1990s. In 2002, the bubble burst, leaving the country in
great poverty (Blustein, 2005). The crash of the Argentinean
economy was followed by political upheaval and economic and
social turmoil. Such social unrest has caused a series of uprisings
in South America, toppling presidents in Argentina (2002),
Bolivia (2003, 2005), and Ecuador (1997, 2000, 2005).
Needless to say, during times of economic and political
upheaval, conservation takes a back seat.

Economy and the Environment
The sustainable use of natural resources has been offered as one
potential solution to economic problems, with the rational use
of wildlife as an alternative to destruction of natural habitats.
Sustained harvest of wild populations has been implemented in
several countries for subsistence (Robinson and Redford 1991,
Shaw 1991, Silva and Strahl 1991, Vickers 1991, Balick and
Mendelson 1992, Bodmer et al. 1997) and commercial pur-
poses such as hides, meat, or live pets (Fitzgerald et al. 1991,
Groom et al. 1991, Beissinger and Bucher 1992, Joanen et al.
1997). For example, several endangered crocodilians are recov-
ering in response to effective harvesting practices (see
Thorbjarnarson et al., 1992 for a review).

Wildlife Management and Conservation in Venezuela
Venezuela has withstood the economic crisis better than other
Latin-American countries, primarily due to the country’s oil
reserves. However, from 1982 to 1998, the economy slowly but
consistently declined. As the economy of the country deterio-
rated and wages fell, people were forced to rely on unconven-
tional resources. For instance, in the past, traditional consump-
tion of Capybara (Hydrochaeris hydrochaeris) meat was restricted
to the week before Easter. More recently, illegal hunting of
Capybaras extended throughout the year, as people resorted to
Capybara meat as a staple. Traditionally, most of the country’s
meat came from Rancho El Frío. For more than 30 years, El Frío
had sustained an estimated population of roughly 30,000

Green Anacondas are ambush predators on aquatic prey or animals
that come to the water to drink. This adult female (SVL 363 cm, 40
kg) regurgitated a 10-kg White-tailed Deer (Odocoileus virginianus)
shortly after capture. 

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This carcass of a Green Anaconda was found on the parched savanna.
Snakes moving in the dry season searching for water occasionally fail
to find a cool refuge during the heat of the day. 

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Capybaras, of which about 10,000 were harvested annually
(Ojasti, 1991). In 1986, I participated in a survey of El Frío
Capybaras that recorded a population of only slightly above
4,000 animals. Later surveys showed an additional decrease in
the population, with poaching acknowledged as the leading
cause of the population crash. This trend is, not surprisingly,
expected to continue and extend to other species as poverty in
the country becomes increasingly prevalent.

Pressures on Anaconda Populations
Although any use of the Green Anaconda (Eunectes murinus) is
prohibited by Venezuelan law, illegal harvests are common.
Between 1988 and 1990, international authorities confiscated
2,138 anaconda skins in Holland that supposedly originated in
Venezuela (Profauna archives). Among the confiscated hides
were skins of E. murinus, which occurs in Venezuela, and of
Yellow Anacondas (E. notaeus), which occur only in southern
South America. When I and my collaborators started studying
anacondas in 1992 (Rivas et al. 2007), I learned that tanneries
were paying the equivalent of U.S. $16.67 per meter of skin.
This is a significant amount for a worker whose income other-
wise averages about $3.50 a day.

Legal low-profile anaconda harvests occur in several South
American nations. In Guyana, anacondas are harvested oppor-
tunistically by fishermen and sold to local tanners (Mirna
Quero, pers. comm.). Yellow Anacondas have been harvested
legally in Argentina (Waller et al., 2007) and illegally in Paraguay
(P. Micucci, pers. comm.). Bolivia had initiated studies investi-
gating the sustainable use of E. murinus, but political unrest

halted the development of the program (J. Aparicio, pers.
comm.).

Farming versus Harvesting Anacondas
The most common methods of extractive wildlife management
are farming, harvesting, or some combination of both. In a
farming model, animals are kept in captivity, a relatively expen-
sive proposition, but practical for animals with fast growth rates,
low maintenance expenses, and capable of being held in high
densities. Traditional farming of Green Anacondas is not prac-
tical. The cost of facilities and maintenance would be prohibi-
tively high. Also, anacondas take several years to reach adult-
hood, and females breed only every other year at best (Rivas,
2000).

However, an “open farm system” may be possible. Large
pregnant females can be found along the riverbanks (Rivas 2000,
Rivas et al. 2007b), caught, kept in captivity, and released after
they deliver. Due to high fertility (Rivas, 2000), a large number
of individuals can be produced quickly. Neonates have a high
natural mortality in the field (Rivas 2000, Rivas et al. 1999,
2001, 2007b). Releasing some percentage of individuals sub-
jected to lower captive mortality rates would presumably equal
the number that would have survived to that age in nature.
Neonates can grow quickly (Holmstrom 1982, Rivas et al.
2007b), and, after a relatively short period in captivity, could
provide scar-free, small-scaled skins with high value on the legal
market.

Anacondas do not make good pets. They quickly outgrow
cages, and become a risk to other pets and even people. They

78 IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 RIVAS

The Venezuelan llanos (= flatlands) are characterized by vast grasslands with ribbons of forest along creeks and rivers. It is an environment of harsh
extremes, severe droughts alternating with floods. The llanos are sparsely populated by humans, with most inhabitants engaged in raising cattle.
The llanos are Venezuela’s greatest repository of wildlife.

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IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 79CONSERVATION OF GREEN ANACONDAS

have an aggressive temperament and never become an easy (or
safe) animal to handle. They also release a fetid musk when dis-
turbed. Nevertheless, anacondas remain popular and potentially
profitable (approximately $250/neonate, retail). The illegal
import of live reptiles for the pet trade continues to grow
(Hoover 1998). This market is hard to control, and the number
of animals being extracted from nature is difficult to quantify. A
legal source of neonates from a sustainable system could serve to
protect the wild population.

Closed-system farming would benefit only the few people
working on the farm, and does not require pristine habitat.
Consequently, farming has at best a modest impact on the local
economy (Thorbjarnarson 1999). So, although sustainable,
farming would not be a constructive conservation method, but
merely business as usual, differing only in the use of a wildlife
commodity. A system of open farming, involving the capture
and post-parturition release of adult females, on the other hand,
has potential as a conservation tool because it requires a pristine
environment where the animals live.

In contrast, in a cropping system, animals are harvested
from the wild; thus a direct link exists between the economic
activity and the conservation of the species and its habitats.
Economic incentives are directly linked to habitat preservation,
and thus cropping has real potential for use as a conservation
tool. Harvesting is best suited for animals that occur in high
densities and are easy to find and catch. Overhead is much lower
than for farming, since the only investment involves finding and
catching animals (product storage and transport to market is an
inevitable component of either method). However, harvesting
has a much greater potential for detrimental effects on natural
populations. Monitoring and controlling the harvest are high
priorities that can be very expensive and potentially troublesome.

Estimating Numbers
Before attempting the management of any species, we must
understand its basic life history. Even modest success at wildlife
management depends upon some knowledge of demography,
especially abundance, rate of increase, fecundity, mortality,
recruitment, and dispersal. Estimates of population size and the
intrinsic rate of increase are necessary in order to calculate the
maximum sustainable yield (MSY; the maximum number of

individuals that can be removed from a population while main-
taining population size).

Because anacondas are secretive, we cannot accurately
determine the total number of animals in any area. An alterna-
tive is to estimate the population size using an index of relative
abundance (e.g., number of snakes seen per km of road). This
way we can propose a conservative MSY, refine it by monitor-
ing the impact of harvesting with repeated surveys, detecting any
problems, and adjusting the take in a timely fashion (Caughley,
1977; Caughley and Sinclair, 1994). To date, however, we lack
any estimate of anaconda abundance, which would require long-
term mark and recapture studies, nor do we have any index of
relative abundance — and none of the traditional methods are
easily applied. One possibility would be to count sightings of
pregnant females along riverbanks or edges of roads, where they
frequently bask. In the interim, the lack of a field-based method
for monitoring the impact of a cropping program, commercially
exploiting anacondas could result in over-harvesting.

Capturing animals presents another challenge. Looking for
anacondas is probably not cost-effective in light of the low fre-
quency of capture that I have encountered (Rivas et al. 2007b).
One option would be to combine harvests of anacondas with
that of other potentially valuable species such as Spectacled
Caimans (Caiman crocodilus), turtles (Podocnemis spp),
Common Iguanas (Iguana iguana), and Common Tegus
(Tupinambis teguixin) (Thorbjarnarson and Velasco 1999). All
of these reptiles occur in relatively high densities and are poten-
tially manageable. However, implementation of a sustainable
management plan for any or all of these species requires basic
knowledge about their populations in any given area — knowl-
edge that is currently lacking.

Hunters typically target the largest individuals (males in
many exploited species), because they provide more skin or
meat. In polygynous species (in which a male mates with more
than one female in a single breeding season), this is potentially
sustainable, since most matings are by only a few males, leaving
a theoretical surplus available for harvesting. Anacondas, how-
ever, are polyandrous (in which a female mates with more than
one male in a single breeding season; Rivas 2000, Rivas and
Burghardt 2001, Rivas et al. 2007a, 2007b) and females are
larger. Also, the largest females contribute the most offspring
(females >340 cm are responsible for nearly 60% of new off-
spring every year, and females >300 cm contribute nearly 75%
of each new generation; Rivas, 2000). In other words, harvest-
ing practices biased for large females would dramatically and
quickly impact population numbers.

Harvesting males would seem to be a feasible alternative.
They are easier to find, can be gathered in greater numbers in
breeding aggregations, and have skins with fewer scars because
they are smaller in size and feed on less dangerous prey (Rivas
2000, Rivas and Burghardt 2001, Rivas et al. 2007b). However,
females that are courted by several males have higher reproduc-
tive success (Rivas, 2000), so the quota of males would have to
be assessed very carefully, and hunters may not accurately dis-
criminate males from females.

Sustained commercial use of large snakes appears to work
in Sumatra, where Reticulated Pythons (Python reticulatus),
Blood Pythons (Python brongersmai), and Short-tailed Pythons

This female Green Anaconda (410 cm SVL, 44 kg) is being courted
by 12 males. 

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(Python curtus) are harvested serendipitously near plantations
and villages (Shine et al., 1999). This method targets mostly
males due to their higher mobility, and produces a variable rate
of harvest that changes with snake abundance. Because hunters
are not targeting snakes, this method of hunting has the poten-
tial to be self-regulating. A drop in the population will produce
a lower encounter rate that will result in a lower harvest. A sim-
ilar method is used for Green Anacondas in Guyana, where fish-
ermen gather snakes opportunistically. Like the python harvest,
this method seems to be sustainable, although quantitative data
are lacking. However, increases in poverty levels of rural inhab-
itants can dramatically increase the levels of harvesting.

Management of Anacondas
Anacondas and other boids are listed in CITES Appendix II,
which requires permits be obtained for any commercial trade.
In Venezuela, anacondas remain abundant due to large expanses
of relatively undisturbed wetland habitats (Rivas et al. 2002). No
legal commercial trade exists, and the illegal market for skins
places little pressure on populations at the moment. Although
edible, anacondas are not eaten. Other than the skin, the only
product of value is the fat. Melted anaconda fat is considered a
medicine for throat problems, asthma, and other respiratory ail-
ments. However, the demand is low and localized. Because sell-
ing anaconda products is illegal, few campesinos engage in har-
vests. Instead, the main reason that local people kill anacondas
is because they fear and dislike them. Arguments that anacon-

das eat poultry, livestock, pets, or even people are often used to
justify killing snakes.

Habitat degradation in the llanos has not yet been a serious
problem, since most land use for cattle involves increasing the
area covered by water for longer periods (Rivas et al. 2002). The
impact of extensive cattle ranching on wildlife here is much
lower than the impact in the United States or other countries
where cattle are kept at higher densities. However, old-fashioned
ranching practices involve cutting forests to ease handling of live-
stock (that often hides in the forest and becomes feral) and allow
easy access to water in dry season. Federal laws prohibit defor-
estation within 50 m of a river, but this regulation is seldom
enforced. Deforestation increased dramatically in the late 1990s.
Riverbanks often develop “caves” that are supported by tree
roots, and these caves are frequently used as refugia by anacon-
das. In the treeless savanna, anacondas have fewer places to hide
and escape from extreme drought. This can be important in
atypical years during which anacondas may be exposed to
extreme heat (Rivas 2000, Rivas et al. 2007b). Caves along seg-
ments of rivers without forest are less abundant and smaller than
those in other areas because the lack of roots allows erosion.
Cutting the forest is a direct threat to anacondas, in addition to
the effects of deforestation on populations of prey species and
other components of forest ecosystems.

Management as a means of incorporating use of anacondas
into economic development plans is difficult, and more research
is needed. Harvesting males, as well as farming of neonates, are

80 IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 RIVAS

Much of the Venezuelan llanos is managed for cattle, with dikes used to hold water for the dry season. Consequently, encounters between cow-
boys and snakes occur frequently. 

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IGUANA  •  VOLUME 14, NUMBER 2  •  JUNE 2007 81CONSERVATION OF GREEN ANACONDAS

possible alternatives that can be explored. However, both prac-
tices involve many logistical problems in addition to ethical issues
that cannot be ignored. Killing animals for human comfort and
leisure is an ongoing theme of heated debates between those con-
cerned with animal welfare and those who manage wildlife for
profit (Robinson 1993, Joanen et al. 1997, Struhsaker 1998,
McLarney 1999, Medellin 1999). New regulations adopted by
the international community regarding import of exotic wildlife,
in the name of conservation or animal welfare, can limit the mar-
ket and jeopardize investments made by producers. Importing
live animals raises ethical issues regarding the welfare of pets that
might end up in the hands of novice pet owners who do not
maintain animals in optimal conditions. In the case of larger rep-
tiles, an additional problem arises when an animal reaches a size
at which it is difficult to keep. Frequently, animals are released in
exotic environments where they usually die of exposure or star-
vation. If they survive and reproduce, further problems arise as a
consequence of exotic invaders in foreign ecosystems (Atkinson
1989, Snow et al. 2007). For instance, Green Anacondas have
been found in the Florida Everglades (Snow et al. 2007),
although evidence of reproduction is lacking.

Many countries have resorted to exploiting wildlife to solve
economic crises. In Venezuela, recommendations resulting from
my research have largely stemmed plans to commercially harvest
anacondas, but less out of concern for the resource than because
the abundance of oil has relieved part of the pressure on the
economy. At the moment, anacondas are at little risk of being
harvested in Venezuela. However, poverty in rural areas through-
out South America, increased human encroachment, and polit-
ical and economic turmoil continue to threaten the species, and
these threats are expected to increase.

I suggest that the least difficult and controversial benefit to
local communities vis-à-vis anacondas is the lure that a “charis-
matic mega-fauna” provides for ecotourism. The llanos has a
tremendous and unrealized potential for ecotourism due to the
large abundance and diversity of wildlife, which is comparable
to that of the Amazonian rainforest (Rodríguez and Rojas-Suarez
1996). However, in the vast savannas of the llanos, animals are
readily spotted and appreciated. Reinvesting profits generated by
ecotourism in the local community in terms of jobs, education,
and welfare are vital if ecotourism is to succeed as a conservation
tool.

Spectacled Caimans in Venezuela
In 1986, the Venezuelan government initiated the harvest
of Spectacled Caimans (Caiman crocodilus). This program
operates on private lands, where owners hire a biologist to
survey the population, and, based on the estimate of pop-
ulation size, Profauna licenses a given quota. Owners hire
people to harvest and process the animals. Skins are bought
by tanners that prepare the skins to crosta (one step of the
tanning process) and sell them to overseas companies that
manufacture the final products. This program provides
some benefits to landowners, to local workers, to biologists
who conduct surveys, and to tanners who process and
export skins. Relying on a prolific species of high commer-
cial value that is relatively easy to count and harvest
(Thorbjarnarson and Velasco 1999), the program would
appear to be a perfect example of conservation manage-
ment.

Regardless of potential and good intentions, the pro-
gram has been engaged in a battle of wits with poachers
who took advantage of loopholes in the regulations. Once
the word got out that a square foot of caiman skin was
worth $40, no safe havens remained for the animals. Every
effort to tweak legislation was matched and overmatched
immediately by new means of circumventing the law.
Landowners would kill and market caimans from sur-
rounding areas to keep their own populations high in
future surveys. Efforts to count skulls and carcasses and
match them with the number of skins were implemented
to ensure that caimans were killed where permits allowed
(carcasses are too heavy to carry on burros, causing poach-
ers to retrieve only skins). This immediately spawned a new

breed of entrepreneur, whose business consisted of renting
truckloads of rotting carcasses to crooked landowners. This
is only one example of the many tricks that Profauna had
to uncover in their effort to implement the program. Many
of the people who were supposed to be involved in the
management of a sustainable resource never perceived it as
anything other than an ephemeral source of wealth.
Consequently, this resulted in dramatic population declines
in many areas (Thorbjarnarson and Velasco 1999). This
program was unsuccessful not only because it failed to con-
vince locals that it was a long-term program capable of pro-
viding sustained revenues, it also failed to provide adequate
economic incentives to the local populace, who never saw
the need to protect the resource.

In 1986, the Venezuelan government initiated the harvest of
Spectacled Caimans (Caiman crocodilus) on private lands.
Photograph copyright © 1996 Florida Museum of Natural
History, used with permission (http://www.flmnh.ufl.edu/
natsci/herpetology/CROCS/Crocpics.htm).

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Yellow Anacondas in Argentina1

An experimental harvest of Yellow Anacondas (Eunectes
notaeus) has been implemented in Formosa Province,

Argentina. The program encouraged indigenous peoples
and rural mestizos to catch snakes over 2.3 m in length that
were found opportunistically during the months of
August–October, the beginning of the warm season. The
2.3-m length was determined by the fact that skins of that
size were 23 cm wide, the minimum necessary for making
purses without patching pieces together. Locals were paid
15–20 pesos (= ~$4–5.40), depending on the size of ani-
mals. No quotas or restrictions on where animals were
caught were imposed. The economic benefits can represent
an important part of the locals’ annual budget in an area
where farmers live on incomes of about $150/year.
However, the people who took the lion’s share of proceeds
were higher in the economic chain. Skins were sold to
shoe- and purse-making factories at $50 per meter. So, a
snake that was, for example, 3 m in length, was bought for
$4 by the tanner and then sold for $150 to make purses
worth several hundred dollars. If local people had benefited
adequately, they would have become guardians and active
stewards of the land. Instead, the program was less of an
effort to manage anacondas than an economic enterprise
using anacondas as a capital commodity.

To place this program into economic and political
contexts, we have to realize that the country’s neoliberal
constitution (1994) established autonomy for the provinces
over their natural resources, which took the decision-mak-
ing away from the central government. Consequently, for
example, if an association of tanners proposed a program
to the central government offering to inject $100K into the
economy, it would not be nearly as tempting for the
nation’s government as it would be for that of a small

province. By allocating the decision-making to smaller
authorities, persuasion of those authorities by offers that
might not be in the best interests of the country or the
environment is much easier.

Yellow Anacondas are smaller than Green Anacondas,
but share a female-biased sexual size dimorphism. Because
2.3 m in length is about the upper limit on the size of males,
this harvesting plan pretty much guarantees the exclusive
harvesting of females. Furthermore, animals are found pri-
marily by searching for individuals basking on dense vege-
tation, and the only snakes that regularly bask are pregnant
females (Rivas, 2000). Conversations with local harvesters
indicated that they anticipated a sharp decline in anacondas
due to the large number of females harvested.

1 Editor’s note: An Argentinian NGO (Fundación Biodi-
versidad) developed and proposed this plan to the National
Government in 2001. It later became the first experimental
approach (possibly worldwide) for the adaptive management
of a boid that has been hunted historically and massively
regardless of any law or biological consideration. The Program
(which generates skins for international trade) deals with a
CITES Appendix II species, requiring its management to com-
ply with Article IV (non-detrimental finding) of the Treaty.
The Fundación Biodiversidad must provide annual reports to
the National Government (CITES Authority) in order to
renew export authorizations and comply with CITES require-
ments. The program is monitored closely, which allows detec-
tion and correction of any problems that might arise. Waller et
al. (2007) noted that:  “For the first time in more than 20
years, biologists were able to design and test a harvest method-
ology for this traditionally exploited species. The experimental
harvest began in 2002, and approximately 5,000 skins of an
average length of 2.6 m were obtained in Formosa each year
between 2002 and 2004, following strict administrative and
technical procedures (Micucci et al., 2006).” An article describ-
ing the plan in detail will appear in the next issue of IGUANA.

An experimental harvest of Yellow Anacondas (Eunectes notaeus) has been implemented in Formosa Province, Argentina. 

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Management versus Conservation
Conservation and use of wildlife are not detached from other
economic and political issues, and we cannot address the former
without considering the latter. Common tendencies are to use
the natural resources for profit without an environmental agenda
by exploiting opportunities and funds provided by conservation.
Such an approach is not sustainable, although it appears to use
natural resources in a “green” manner. In fact, such activities may
harm conservation efforts. The use and depletion of natural
resources in the name of conservation give it a negative image,
which, in turn, drains funds and distracts attention from real
solutions.

Business or Conservation?
When management is used for conservation, the economic
incentives are tools for encouraging local people to protect the
environment. The purpose of assigning an economic value to a
resource is to provide stewards of the land reasons for protecting
it. The alternative is exploiting the environment for commercial
gain. The latter, however, may involve businesses that use
resources in a sustainable manner and are environmentally
friendly or businesses that loot the environment for short-term
profit. While sustainable use is a legitimate practice, it differs
from conservation measures in that the priority is maximizing
gains.

Impact of Neoliberalism on Conservation
Despite evident declines in Venezuelan caiman populations (see
Box) (Thorbjarnarson and Velasco, 1999), Profauna chose to
ignore repeated warnings of over-exploitation from the scientific
community, probably because the agency depended on the rev-
enues generated by sales of caiman skins. A program is inherently
flawed when the people who administer a resource are depend-
ent on the exploitation of that resource. This is an example of a
larger problem. In the late 1980s, Venezuela was heavily influ-
enced by a neoliberal agenda (Larrea, 2004). Recommended
measures for economic development (SAPs) demanded that the
government did not sponsor research or any other activities that
were not linked to administration of resources; instead, self-
financing became the mantra of the relevant governmental agen-
cies. The laws of supply-and-demand should rule the system
(Navarro-Jimenez 2004). However, because managers had to
compromise their own jobs if they took any action to stop the
program, they did not respond to evidence of declines. In fact,
when the program slowed solely due to the increasingly low den-
sity of caimans, Profauna underwent major structural changes,
downsized, and eventually disappeared.

The Argentinean program for harvesting Yellow Anacondas
(see Box) also embraced a neoliberal agenda. During the late
1990s, economic growth had slowed and the nation was facing
serious economic problems. By the end of 2001, the IMF pulled
out and the economy crashed (Blustein 2005), rendering imper-
ative the exploitation of a natural resource. Tanners in Formosa
Province provided a fund of $100,000 for harvesting anacondas,
a juicy contribution to a stagnant economy. The whole system
depended on the urgent need to produce cash to ameliorate the

economic crises. Turning down a business opportunity was not
an option.

The Fallacy of Tylenol Conservation
Choosing to ignore or deny the impact of macroeconomics on
conservation will not lead to a solution. We cannot address the
problems of conservation unless we acknowledge the root cause.
Ignoring the big problems by trying to address those that are eas-
ier or cheaper to solve is the fallacy of “Tylenol Conservation.”
Taking a painkiller rather than addressing the underlying prob-
lem often results in the need for more and stronger painkillers
as time passes. A similar approach in conservation creates an illu-
sion that we are working to make a difference while distracting
us from addressing the real issues.

Another example of Tylenol conservation is the tendency
to identify and protect areas of high diversity, when the real solu-
tion is addressing threats to the land. Protective legislation is, like
a painkiller, a handy tool, but not a solution to the problem. In
Latin America, extreme poverty is the underlying cause of con-
servation problems. Protecting a piece of land, education, and
providing some economic relief for locals through wildlife man-
agement or ecotourism are laudatory, but are only painkillers
that provide, at best, only temporary relief.

The main point with which I want to leave the reader is
that conservationists must realize that politics and macroeco-
nomics are not dirty words, but simply disciplines in which we
need to be involved. If we really want to make a difference in
conservation, we need to attack the roots of problems and causes
— and the origins of conservation problems are rarely biologi-
cal. Instead, economic, social, and political issues are often
responsible. Integrating concerns about environmental degrada-
tion and loss of biodiversity with support of movements for sus-
tainable economies and perhaps even anti-neoliberal globaliza-
tion movements can result in more effective solutions with
better chances for long-term successes.

Acknowledgements
I thanks Sarah Corey and William Hayes for relevant comments
on earlier versions of this article. I also thank COVEGAN and
Estacion Biológica Hato El Frío for logistical support and assis-
tance during fieldwork.

Bundling Green Anaconda skins for transport to the tanning plants.

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The most geographically and ecologically widespread of
the eight currently recognized species of the

Neotropical treeboa genus Corallus, C. hortulanus ranges
from Amazonian Colombia and Venezuela, through the
Guianas, throughout Amazonian Brazil, Ecuador, Peru, and
Bolivia, and south into Brazil’s Atlantic Forest to about 26º
08’ south latitude, and on Ilha Grande (off southeastern
Brazil). It occurs in diverse habitats, including primary and
secondary rainforest, mixed forest, second growth, palm
forests, swamp forest, cerrado, caatinga (where it is proba-
bly confined to gallery forests), and savanna/grassland with
stands of trees. It is often associated with edge situations
and may be especially common in trees at the margins of
bodies of water (rivers, lagoons, lakes). It also exploits heav-
ily disturbed situations, such as fruit orchards (bananas,
cacao), and will enter human edifices (outbuildings,
homes), likely seeking shade, a diurnal retreat, or a human
commensal rodent. Altitudinal distribution is from sea level
to about 915 m, although it is uncommon above 300 m. 

Few snake species worldwide can compete with
Corallus hortulanus when it comes to variation in color and
pattern. Dorsal ground color of the boas may be various
shades of yellow, orange, gray, taupe, and/or brown. They
may be virtually patternless yellow or orange, or have an
ellipse-like shape that may be a shade of the ground color
or in sharp contrast to it, or it may appear extremely mot-
tled (but close inspection usually reveals the ellipse shape).

Amazon Treeboas are nocturnal and, as the name
implies, largely arboreal. Their bodies are laterally com-
pressed, and snakes may attain snout-vent lengths (SVL)
over 1.6 m, and can reach SVLs of 1.8–1.9 m. Both active
and ambush foraging strategies are employed, and the diet
consists almost entirely of endotherms. When young
(<750 mm SVL), birds (and, to a lesser degree, bats) com-

prise a significant portion of their diet (likely captured via
active foraging while the birds are at roost) but, with
increasing size, mammals (especially rodents) become their
principal prey. Frogs and lizards are taken infrequently by
C. hortulanus.

References
Henderson, R.W. 2002. Neotropical Treeboas: Natural History of the Corallus

hortulanus Complex. Krieger Publishing Co., Malabar, Florida.

Pizzatto, L., O.A.V. Marques, and M. Martins. 2007. Ecomorphology of
boine snakes, with emphasis on South American forms, pp. 35–48.
In: R.W. Henderson and R. Powell (eds.), Biology of the Boas and
Pythons. Eagle Mountain Publishing, Eagle Mountain, Utah.

S P E C I E S  P R O F I L E

Amazon Treeboa (Corallus hortulanus)
Robert W. Henderson

Milwaukee Public Museum

Although Corallus hortulanus demonstrates tremendous color and
pattern variation throughout its range, this individual exhibits a
much higher percentage of white scales than typically observed.
It was captured in a small section of bamboo forest near the Rio
Cristalino in northern Mato Grosso, Brazil. The habitat is tran-
sitional between southern Amazonian rainforest and the vast
savanna-like Cerrado to the south. A second snake with similar
coloration was found several days later. Whether these individu-
als are just variants of an extremely variable species or a color pat-
tern anomaly is unknown.

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